This disclosure relates to polycarbonate compositions, articles formed therefrom, and their methods of manufacture, and in particular to polycarbonate-polysiloxane copolymer compositions with advantageous properties such as improved aesthetic properties, good impact, or desirable chemical resistance.
Polycarbonate homopolymers and polycarbonate copolymers are useful in a wide variety of applications at least in part because of their good balance of properties, such as moldability, heat resistance and impact properties, among others. Despite extensive research on these materials over the years, there still remains a need in the art for improved polycarbonate compositions that meet increasingly stringent industry standards.
For example, polycarbonate-polysiloxane copolymers can have good mechanical properties and low temperature impact resistance. However, blends of a polycarbonate homopolymer with such a polycarbonate-polysiloxane can result in poor aesthetics of molded parts. Aesthetic defects can include excess haze, limited color space capability, pearlescence, or other surface defects related to molding such as streaks and flow lines. To improve the aesthetics, other desirable properties such as low temperature impact and chemical resistance may be comprised. There accordingly remains a need in the art for polycarbonate compositions that can have balanced aesthetics, low temperature impact, and chemical resistance.